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FHWA Home / Safety / Roadway Departure / Safety Eligibility Letter

Safety Eligibility Letter CC-113

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U.S. Department of Transportation
Federal Highway Administration

1200 New Jersey Ave. S.E.
Washington, D.C. 20590

December 13, 2010

In Reply Refer To: HSST/CC-113

Mr. Gerrit Dyke, P.E.
Barrier Systems, Inc.
3333 Vaca Valley Parkway, Suite 800
Vacaville, CA 95688

Dear Mr. Dyke:

This letter is in response to your request for the Federal Highway Administration (FHWA) acceptance of a roadside safety device for use on the National Highway System (NHS).

Name of system: Raptor Crash Cushion
Type of system: Crash Cushion for narrow vertical objects
Test Level: NCHRP Report 350 Test Level 1 (TL-1)
Testing conducted by: Safe Technologies, Inc.
Task Force 13 Designator: SCI25
Date of request: June 1, 2010

You requested that we find this system acceptable for use on the NHS under the provisions of the National Cooperative Highway Research Program (NCHRP) Report 350 “Recommended Procedures for the Safety Performance Evaluation of Highway Features.”

Decision:
The following device was found acceptable, with details provided below:

Requirements
Roadside safety devices should meet the guidelines contained in the NCHRP Report 350 or the American Association of State Highway and Transportation Officials’ Manual for Assessing Safety Hardware. The FHWA Memorandum “Identifying Acceptable Highway Safety Features” of July 25, 1997, provides further guidance on crash testing requirements of longitudinal barriers.

Description
The Raptor Crash Cushion is a non-redirective gating crash cushion. The Raptor consists of two identical halves that are installed back to back around a hazard, and connected to become a single complete system. The two halves are held together using ten connectors with twenty bolts and washers. There is no separate anchoring because the system is designed to sit directly on the ground. The Raptor is designed primarily to deflect impacting vehicles by rotating upon impact. Enclosure 1 illustrates details of this system.

Crash Testing
The Raptor crash cushion system was crash tested according to NCHRP Report 350 test designations 1-41, 1-42, and 1-43 by Safe Technologies Inc. Enclosures 2 through 4 summarize the results of the tests.

Findings
According to NCHRP Report 350, tests 1-40 through 1-44 are to be conducted for TL-1 non-redirective gating crash cushion evaluation. The Raptor system was crash tested under all of these required tests, except for tests 1-40 and 1-44. The system described above and shown in Enclosure 1 passed all tests that were conducted. Occupant Impact Velocities (OIV) associated with tests 1-41 and 1-42 were 12 m/s, which is the maximum allowed for OIV. The OIV associated with test 1-43 was estimated at 10 m/s. The Occupant Ridedown Acceleration (ORA) for all tests were below the “preferred” limit defined in NCHRP 350.

In your letter you have requested tests 1-40 and 1-44 be waived. The waiver of test 1-40 is accepted on the grounds that test 1-42 is historically more critical than test 1-40. Test 1-44 is intended to demonstrate whether the system will redirect the errant vehicle or cushion its impact, or a combination of both. The main purpose of the Raptor crash cushion system is to shield a vertical column that may be struck head-on by absorbing and dissipating the kinetic energy of impacting vehicles, or by rotating and deflecting the vehicle from a head-on impact with the hazard. Therefore, the re-directive capability of the system to withstand a hit on the side is not as critical as its energy absorbing or rotational capability. Consequently, I concur that test 1-44 can be waived given the successful results of test 1-43.

In your letter you have also requested FHWA’s acceptance based on the following installation considerations for the Raptor system:

The above installation considerations are all accepted. However, it should be noted that the Raptor must be installed on a clean and level surface that is capable of supporting the weight of the system and permits the system to rotate during oblique impacts.

Therefore, the system described in the requests above and detailed in the enclosed drawings is acceptable for use on the NHS under the range of conditions tested, when such use is acceptable to a highway agency.

Please note the following standard provisions that apply to FHWA letters of acceptance:

 

Sincerely yours,

/* Signature of Michael S. Griffith */
Michael S. Griffith
Director, Office of Safety Technologies
Office of Safety

Enclosures

Page last modified on January 17, 2013.
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